Embodiments include semiconductor packages and methods of forming the semiconductor packages. A semiconductor package includes a die over a substrate, a first conductive layer over the die, and a cavity resonator antenna over the first conductive layer and substrate. The cavity resonator antenna includes a conductive cavity, a cavity region, and a plurality of interconnects. The conductive cavity is over the first conductive layer and surrounds the cavity region. The semiconductor package also includes a second conductive layer over the cavity resonator antenna, first conductive layer, and substrate. The conductive cavity may extend vertically from the first conductive layer to the second conductive layer. The cavity region may be embedded with the conductive cavity, the first conductive layer, and the second conductive layer. The plurality of interconnects may include first, second, and third interconnects. The first interconnects may include through-mold vias (TMVs), through-silicon vias (TSVs), conductive sidewalls, or conductive trenches.